/*
 * Copyright 2021 Shulie Technology, Co.Ltd
 * Email: shulie@shulie.io
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package io.shulie.surge.data.runtime.disruptor;

import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class TimeoutBlockingWaitStrategy implements WaitStrategy
{
	private final Lock lock = new ReentrantLock();
	private final Condition processorNotifyCondition = lock.newCondition();
	private final long timeoutInNanos;

	public TimeoutBlockingWaitStrategy(final long timeout, final TimeUnit units)
	{
		timeoutInNanos = units.toNanos(timeout);
	}

	@Override
	public long waitFor(final long sequence,
			final Sequence cursorSequence,
			final Sequence dependentSequence,
			final SequenceBarrier barrier)
			throws AlertException, InterruptedException, TimeoutException
	{
		long nanos = timeoutInNanos;

		long availableSequence;
		if ((availableSequence = cursorSequence.get()) < sequence)
		{
			lock.lock();
			try
			{
				while ((availableSequence = cursorSequence.get()) < sequence)
				{
					barrier.checkAlert();
					nanos = processorNotifyCondition.awaitNanos(nanos);
					if (nanos <= 0)
					{
						throw TimeoutException.INSTANCE;
					}
				}
			} finally
			{
				lock.unlock();
			}
		}

		while ((availableSequence = dependentSequence.get()) < sequence)
		{
			barrier.checkAlert();
		}

		return availableSequence;
	}

	@Override
	public void signalAllWhenBlocking()
	{
		lock.lock();
		try
		{
			processorNotifyCondition.signalAll();
		} finally
		{
			lock.unlock();
		}
	}

}
